Apparatus for treating solid materials with volatile organic solvents



July 8, 1941.

G. EDHOFER EI'AL APPARATUS FOR TREAiING SOLID MATERIALS WITH VOLATILEORGANIC SOLVENTS Filed Feb. 8, 1938 INVENTORS Gevfiaib/ro/ s/zG'ao/PaWoz/ r KM ALA z ATTO Y Patented July 8, 1941 UNITED STATES PATENTOFFICE APPARATUS FOR TREATING SOLID MATE- RIALS WITH -VOLATILE ORGANICSOL- VENTS Georg Edhofer and Georg Wolfl, Munich, Germany, 'assignors toDr. Alexander Wacker .Ges.

fiir elektrochemische Industrie in. Munich, Germany,- a corporationApplication February s, 1938, Serial No. 189,412 In Germany May 4, 19378 Claims. (01.202-169) The present invention relates to a method andapparatus for treating solid material with volatile organic solvents.

It is well known to clean articles made of metal 'or other solidmaterials which are covered with grease by treatment with organicvolatile solvents such as trichlorethylene, perchlorethylene,carbon-tetrachloride, benzine, benzol, and the like, and to use for thispurpose a cleaning vessel which is filledwith cold, heated or vaporizedsolvent and which may be divided into a plurality of subchambers-intowhich the materials to be a preand after-cleaning treatment. It is alsowell known to use immersing chambers which are filled with solvents ofdifierent temperature or of diiferent aggregate state, sothat, forexample, pre-cleaning may be carried out in a solvent having atemperature which is below its boiling point, and after-cleaning is.carried out in vaporized of an apparatus suitable to carry out ourpresent invention.

Figure 2 shows adetail of the apparatus shown in Figure 1, and

Figure 3 shows a modification of .the'detail shown in Figure 2.

- Figure 4 shows a modification of the detail shown in Figure 3.

. treated are immersed consecutively for obtaining solvent whereby itcannot be avoided that some I of the solvent adhering to the articlesvaporizes when the articles are thansferred from one immersing chamberto the other whereby the goods are completely or partially dried.

Experience has shown that for certain kindsof goods it is of advantageto prevent any drying, if only partial, of the goods in between theindividual treating steps and it is an object of the present inventionto provide a method and means whereby the goods are at first immersed inaliquid solvent, the temperature of which is below the boiling point,whereby the articles are pre-cleaned and then directly transferred intoa chamber fed with solvent in vapor state, which chamberis sealed at thebottom with the'same.

solvent in liquid state, so that at the transition of the goods from thefirst to the second chamber,

no contact of the goods with air takes place. Only" after the goods havefurther been cleaned by the solvent condensed on the goods are theybrought into a cooled air zone where the rest of the solvent stilladhering to the goods vaporizes and the goods are quickly dried. Withthis method the vapor of the solvent is in direct communication with theliquid solvent so that the latter may graduallybe heated up to theboiling point, ,which is not desired, and means are therefore provided,according to the present invention, to cool the .liquid and maintain itstemperature below the boiling point.

Further and other objects of the present invention will be hereinafterset forth in the accompanylng specification and claims and shown in thedrawing which, by way-of illustration, shows what we now consider to be.a preferred embodiment of our invention.

In the drawing- Figure 1 is a diagrammatic cross sectional view Likeparts are designated by like numerals in all figures of the drawing.

i represents a cleaning vessel, which is com- I pletely closed with theexception of a lateral opening 2 for the insertion of the goods and thelower part 3 of'which is filled with a liquid solvent. By means of thevertical partition 4', a

shaft-like chamber 5 is formed, the bottom of which is sealed by theliquid cleaning solvent. A tube 6 terminates into the lower part ofchamber 5, through which tube solvent vapor is introduced which isproduced in a heated evaporator l which is partly filled with a liquidsolvent. The height of the vapor zone in chamber 5 is defined by theposition of the cooling coils 8 located adjacent to the walls of chamber5, because excess vapor con-- pass thereby the loading opening 2 throughwhich the goods to be treated are introduced and filled into and takenout of the baskets; the filled baskets are immersed and taken throughthe lower part 3, which is filled with cleaning fluid and conductedunderneath the partition 4 and upwardly into shaft 5. In this shaft,after leaving the cleaning liquid, the baskets pass first through a zoneIII which is filled with vaporized solvent whereby anafter-cleaningeflect is obtained by said vapor which condenses on thesurfaces of the goods, and then through a cooled air zone which islocated above'the vapor zone. In

- .said air zone the heated goods are cooled and dried, whereafter theyare brought back over the top of the partition 4 into the neighborhoodof the opening 2 where they are taken from the baskets, fully cleaned.The baskets are then re-.

filled with new and unclean goods.

The space 3 communicates with the evaporator 1 through the conduit Hwhereby the liquid level in the cleaning vessel and in the evaporatorare maintained alike. The solvent carries out a complete cycle; itenterschamber 5 in vapor state,

is condensed, and the condensate returned to the evaporator. I

In order to obtain efllcient' condensation of the vapor on the goods, itis desirable thatthe latprocess, design, scribed, for obviousmodifications will occur to ter enter the .vapor zone at low temperatureand the temperature of the goodsis not increased while passing throughthe liquid. Since continuously hot condensate drips into the liquid fromthe vapor'zone II and the cooling tubes I therein, the heat sointroduced must be removed;

this is done by means of cooling tubes |2 located and a light draft'ofair into the vessel through opening 2 is created. The tube connection Iis widened out to a funnel shaped inlet IS, the upper wide opening ofwhich funnel includes a platform means which is located beneath thebasket standing at the opening 2 so that vapor adhering to said basketand goods-therein is completely removed. I

The chains 9 and 9 are moved by connecting a crank to be operated by.hand or, as shown, a motor 20, to one of the rollers IS. The operationof the motor is preferably automatically stopped when a basket filledwith cleaned goods reaches the loading opening 2, and is started by theoperator when the basket is refilled with new, unclean goods. In casemotor is an electric motor, this may be done by arranging a switch 2|:located at one end of a two arm lever 22 which is turned clockwise whena basket ll contacts its free end 23; thereby switch 2| is opened andthe current for operating the motor 2|! interrupted. To lever 22' also'afoot pedal 25 is connected by means of a connecting rod 24. Upondepression of said pedal by the operator, the switch 2| is closed andcurrent is admitted to the motor 20.

Instead of baskets having cross bars which connect chains 9 and 9' asshown in Figures 1 and Z, baskets H! as shown in Figure 3 may be usedhaving lateral shafts 26 and 21 whereby one of said shafts, for example21, is provided with a crank adapted to contact a stationary abutment 28in the vessel I. Whenever said abutment is contacted, the basket I0 isrevolved about the axis 26-21 whereby the cleaning action is increasedand also quick and complete drying of the goods, particularly goods ofhollow construction, is assured. Provisions for revolving the basketsmay be situated at any point of the apparatus, for example, in theliquid zone and/or in the vapor zone and/or in the drying zone.

Insteadof providing a crank and abutment a pinion 29 and a rack 30 maybe used as shown in Figure 4 whereby the baskets are revolved all theway while they travel through the solvent in liquid state, in vaporstate and through the drying zone or, if the racks are arranged atcertain parts only of the path of the baskets the baskets arecontinuously revolved while they travel through said parts.

While we believe the above-described embodiments of our invention to bepreferred embodiments, we wish it-to beunderstood that we do not desireto be limited'to the exact details of and construction shown and deaperson skilled in the art. For example, the opening 2 may the wall; aplurality of immersion chambers be arranged on top instead of on filledwith cleaning liquid may be arranged in the lower part of vessel l andpassed by the goods to be cleaned consecutively before they are takeninto the vapor zone.

We claim:

1. The apparatus for treating solid goods with a volatile solventcomprising, in combination, a

vessel having a lower portion which is filled with said solvent inliquid state, a partition in said vessel, said partition having a lowerpart immersed in said solvent in liquid state and forming a loadingchamber and a treating chamber within said vessel, the lower parts ofsaid chambers being sealed from one another by means 0! said liquidsolvent, an evaporator for said solvent, said evaporator having a vaporspace, a conduit connected to and connecting said vapor space and saidtreating chamber and terminating in said treating chamber in a mouthwhich is positioned above the level of the solvent in liquid state,cooling means in said treating chamber and being positioned above themouth of said conduit whereby solvent vapor condenses on said coolingmeans, an opening in said loading chamber for introducing into andremoving the goods to be treated from said vessel, conduits terminatinginto said vessel adjacent to said opening and means producing in saidconduits a pressure which is lower than the pressure prevailing in saidvessel, one of said second-mentioned conduits terminating below saidopening in said vesse'l and having a furmel configuration flaring outinto said loading chamber.

2. The apparatus for treating solid goods with a volatile solventcomprising a vessel having a lower portion filled with said solvent inliquid state, a partition in said vessel, said partition having a lowerpart immersed in said solvent in liquid state and forming shaftlikechambers within said vessel, the lower parts of said chambers beingsealed from one another by means of said liquid solvent, an evaporatorfor said solvent, said evaporator having a vapor space, a conduitconnected to and connecting said vapor space and one of said chambersand terminating in said chamber in a mouth positioned above the level ofthe solvent in liquid state, cooling means in that one of said chambersto which said conduit is connected, said cooling means being positionedabove the mouth of said conduit whereby solvent adapted to temporarilycooperate with said contact means, whereby upon contact of said contactmeans and said abutting means said containers are temporarily moved withrespect to said conveyor means and the position of the goods in saidcontainers is changed.

3. The apparatus for treating solid goods with a volatile solventcomprising a vessel subdivided into a plurality of chambers, one of saidchambers being partly filled with said solvent in liquid state, andpartly with said solvent in vapor state, an endless conveyor meanswithin said vessel and moving consecutively through said chambers and vtainers is changed.

through said solvent in liquid state and subsesaid treating chamber andterminating in said quently through said solvent in vapor state, con- Itainers for the goods toibe treated directly movably connected to saidconveyor means, contact means connected to said containers, and abuttingmeans spaced apart and being connected to a stationary part of saidvessel and being adapted to temporarily cooperate with said contactmeans,

whereby, upon contact of said contact means and said abuttingmeans, saidcontainers are temporarily moved withrespect to said conveyor means andthe position of the goods in said con- 4. The apparatus for treatingsolid a volatile solvent comprising a vessel subdivided into a pluralityof chambers, an endless conveyor means within said vessel and movingconsecutively through said chambers, containers for the goods to betreated, a shaft-like member individually connectedto said containersand to said conveyor means for individually revolvably connecting saidcontalnerswith said conveyor means, a crank connected with saidshaft-like member and crank actuating means spaced apart and beingconnected with said vessel and being adaptgoods with ing and extendinginto said vessel, an endless conveyor means within said vesselcomprising containers for theagoods to be treated, and being adapted totransport the goods to be treated con-'- secutively over said platformmeans and through ed to temporarily actuate said crank, whereby saidcontainers are temporarily revolved.

5. An apparatus for treating work with a, vola- V tile solvent, saidapparatus comprising a vessel having a lower portion containing solventin liquid state, a partition in' said vessel and having a lower partimmersed in the liquid solvent, said said chambers, suction meansconnected with and terminating in said platform means and causing asuction efl'ect adjacent to said opening and on said containers andgoods from below ing over'said platform means.

7. The apparatus. for treatingsolid goods with a volatile solventcomprising, in combination, a vessel having a lower portion filled withsaid solvent in liquidstate, a partition in said vessel, said partitionhaving a, lower part immersed in said solvent in liquid state andforming. shaft-like chambers within said'vessel, the lower parts of saidchambers being sealed from one another by -means of said liquid solvent,an evaporator for said solvent, said evaporator having a vapor space, aconduit connected to and connecting said vapor space andone of saidchambers and terminating in said chamber in a mouth positioned above thelevel of the solvent in liquid state, cooling means in that one of saidchambers to which said conduit is connected, said cooling means beingpositioned above the mouth of said conduit whereby solvent vaporcondenses on said cooling means.

and a vapor filled zone is created in the chamber to which said conduitis connected between-the a liquid level and the mouth of said conduit,and

and preventing vaporisation in said intake chamber, solventvapor supplymeans terminating in said treating chamber, cooling means disposed insaid treating chamber and above the surface of the liquid solvent andabove said vapor supply means for condensing the vapor and dripping thehot condensate into the liquid solvent'in said treatingchamber andcreating a vapor treating zone between the liquid surface and saidcooling means and a substantially vapor free zone above said coolingmeans, and work conveyor means disposed completely in said vessel andextending a all around said portion for transporting the work 'avolatile solvent comprising a vessel having an opening for taking thegoods to be treated into and removing same from said vessel, said vesselhaving a lower portion which is filled with said solvent in liquidstate, a partition in said vessel,

said partition having a lower part immersed in said solvent in liquidstate and forming a loading chamber and a treating chamber within saidvessel, the lower parts of said chambers being an endless conveyor meansdisposed completely within said vessel and extending around saidpartition and being adapted to transport the oods to be treatedconsecutively from one of said chambers, through said solvent inliqi'iid state, underneath said partition, through said vapor zone,above-said partition, and back into 'the chamber from which theystarted.

8. The apparatus for treating solid goods with a volatile solventcomprising, in combination, a vessel having a lower portion filled withsaid solvent in liquid state, a partition in said vessel, said partitionhaving a lower part immersed, in said solvent in liquid state andforming shaft-like chambers within said vessel, the lower parts ofsaid'chambers being sealed from one another by, means of said liquidsolvent, an evaporator for saidsolvent, said evaporator having .a vaporspace, aconduit connected to and connecting said vapor space and one ofsaid chambers and terminating in said chamber in a mouth positionedabove the level of the solvent in liquid state, cooling means in thatone of said chambers to which said conduit is connected, said coolingmeans being positioned above the mouth of said conduit whereby solventvapor condenses on said cooling means, and an endless conveyor meansdisposed entirely within said Vessel-and around said partition formoving the goods to be treated sealed from one another by means of saidliquid solvent, an evaporator for said solvent, said evaporator having avapor space, a conduit con-, nected to and connecting said vapor spaceand around, saidpartition from one of said chambers into the. other andback into the first chamber.

" GEORG EDHOFER. cacao. wow.

when pass-

